Piston



Jan. 12 1926. I

w. c. BAUER PISTQN 2 Sheets-Sheet 1 Filed March 30, 1925 INVENTOR fiZa/ferfiazzar ATTORNEY Jan. 12 ,1926.

I W. C. BAUER PISTON 2 Sheets-Sheet 2 Filed March 30, 1925 uwsmron ltQ/fr 61.54126/7 By ATTORNEY To all whom it may concern: v

Patented Jan. 12; 1926.

UNITED STAT S PATENT OFFICE.

WALTER C. BAUER, LINDEN, NEW JERSEY, ASSIGNOR TO UPPERCU CADILLAC GOR- PORATION, A CORPORATION OF 'NEW YORK.

PISTON.

Application filed March 30, 1925.

Be it known thatI, WALTER C. BAUER, a citizen of the United States, and a resident of Linden, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Pistons, of which the following is a specification, reference being had to the accompanying drawings, forming part of this specification.

This invention relates to pistons and more particularly to those used in conjunction with internal combustion engines.

The embodiment as herein disclosed features a piston of the composite type having an inner or main portion formed of relatively soft thermally.- conductive material and an outer sleeve portion formed of rela tively hard wear resisting material.

One of. the objects of the present invention is to provide a novel and improved pis' ton of the type referred to in which the inner thermally conductive portion is so formed as to permit circumferential expansion of the same whilst preventing therein radial distortion and its resultant detrimen- .tal efl'ect upon the outer contiguous sleeve portion.

A further object of the invention is to provide an improved form of piston in which the wrist in bosses are formed as an integral part 0 the outer or harder portion, the parts being so fabricated as to permit the bosses to extend through the inner thermallyconductive portion in a manner asto allow separation of the parts.

A still further object of the invention is to provide a piston having the features above described in which the parts are few and so constructed that they can be readily as sembled or disassembled,'thus' permitting the replacement of any of the parts.

Composite pistons having several parts respectivel formed of non-analogous ma-.

terial are nown in the art and have been found to possess certain advantages over the t ev in common use. Pistons of this type, owever, usually have the wrist pinbearing formed as part of the main or heat conducting portion which must necessarily Serial No. 19,875.

This relatively softportion being disposed so as to absorb and dissipate the heat generally by the explosion, also directly receives the full effect of the explosive force which must be transmitted to the wrist pin bearings in the operation of the motor. Therefore, the common practice of having these bearings part of the aforesaid relatively soft portion is manifestly a disadvantage which has been obviated by my improved'construction in the present invention.

Composite pistons having heat conducting properties are usually provided with a skirt or sleeve portion adapted to resist wear and which surrounds the main body portion. This main body portion being exposed to a high degree of heat and-having great ex ansive characteristics due to the nature 0 the alloy employed in the manufacture of the same, must necessarily be subject to considerabe circumferential expansion, and where no provisions have been made to the contrary this circumferential expansion results in radial distortion which reacts upon the relatively thin sleeve portion.v

without any appreciable effect upon the sleeve portion.

I To these and other ends, the lnvention consists in certain improvements and the combination and arrangement of parts, all as will be more fully hereinafter described,

the features of novelty being pointed out particularly in the claims at the end of they specification.

In the drawings Figure 1 is a vertical section of the preferred form of my invention showing the parts in their assembled relation. Figure 2 is a vertical section taken at right angles to that of Fig. 1.

Figure 3 is a vertical section illustrating a modified embodiment of the form shown in'Figs. ,1 and 2.

Figure 4 1s a vertical section taken at right angles to that of Fig. 3.

. circumferential expansion.

In the present instance with reference tosleeve or skirt 11 preferably constructed of.

cast iron. The parts 10 and 11 are held in their assembled relation by the retaining nut 12 which engages the body portion 10 by means of the screw threads.

On the skirt portion 11, which as has been said, is preferably constructed of cast iron, there are formed the wrist pin bosses 13, connected by a bridge 13.

The body portion 10 is provided with openings 14 which are disposed diametrically opposite one another and extend to the lower edge. These openings provide the necessary clearance for the wrist pin bosses 13 and bridge 13 which extend through the aluminum body, in addition to which these openings permit said body portion to expand circumferentially without causing any radical distortion therein.

The skirt portion 11 can be made relatively thin and so constructed as to snugly fit the interior of the cylinder, there being no danger of binding at this point due to the openings 14 which effectively prevent expansion of the aluminum body and its contiguous skirt portion. In this manner I have eliminated the objectional piston slap incidental to the o erationof engines provided with pistons aving a sloppy fit.

As shown in the drawings, I have provideda clearance 15between the body and the skirt with a suitable gap or opening 16 to permit the oil to enter between these walls, it having been found that the oil materially assists in conducting the heat away from the -main body portion; The openings 14 provide the necessary drainage for the oil in addition to which suitable apertures 17 may be formed in the lower portion of the body 10 for this urpose.

With reference to Figs. 3 and 4 there is shown alternative construction in which the wrist pin bearings 13 are formed as part of the main body portion 10, the openings 14 still being retained in the bod 10 to permit tion 11 may be provided with the bridge 13 to give added strength or dispensed with whena floating wrist pin is contemplated.

It 'shouldbe noted that the piston as herein shown and described comprises two main parts of light and simple const uction which are readily assembled by slipping one art over the other and securing them in fixed relation by the retaining nut.

Variation may be resorted to within the scope of the invention and, ortions of the improvements may be use without the others whilst not departing from the spirit of the invention.

he sleeve por- Having thus described my invention, I claim 1. A piston comprising, an inner body portion, an outer sleeve portion having wrist pin bearings integral therewith, said wrist pin bearings extending through said body portion in a manner as to permit separation of the parts.

2. A piston comprising, an inner body portion provided with openings, an outer sleeve portion having wrist pin bearings integral therewith, said bearings extending through said body portion by means of the openings therein in a manner as to permit separation of the parts, and a means to retain said portions in assembled relation.

3'. A composite piston including, a body portion formed of thermally conductive material, a sleeve portion formed of relatively hard material mounted on the body portion, wrist pin bearings formed integral with the sleeve portion, said body portion provided with means to permit circumferential expansion thereof without radial extension, and

means to retain said portions in assembled relation in a manner as to permit separation of the parts.

4. A composite piston comprising, a main body formed of thermally conductive material, said body provided with means adapted to permit circumferential expansion of the lower portion thereof without radial extension, a sleeve portion formed of relatively hard wear resisting material secured to said lower portion of the body, and wrist pin bosses formed integral with said sleeve portion and extending through said body.

5. A composite piston comprising, an inner main body, said body provided with means comprising cut away portions forming/ openings adapted to permit circ ferential expansion of the lower portion here of without causing radial extension, anouter portion, said main body having portions cut away to permit circumferential expansion thereof and to further permit the wrist pin hearings to pass through said body.

7. A piston of the class described, comprising a main body having diametrically opposite ortione cut away to provide openings whic extend from the lower edge to a oint intermediate its ends, a sleeve portiondisposed externally of said body and contiguous with a portion thereof, wrist pin bearings integral with the sleeve portion and extending through said body by means of said 0 enings, and a retaining member adaptec to hold the parts in operative relation.

8. In a piston, the combination of a main body portion, a sleeve member disposed externally thereof and having a portion extending through said body portion, means-on the body portion comprising peripheral interruptions adapted to permit circumferential expansion of the body without radial distention.

9. In a piston, the combination of a main body portion, an out-enrelatively thin sleeve having contact therewith and having an integral portion extending through said body portion by means of circumferential interruptions formed in the body adapted to permit expansion of said body without creating radial pressure-upon the sleeve portion.

10. In a composite piston, the combination of a main body portion, an outer relatively thin contiguous sleeve having a portion ex-,

tending through said body by means of openings formed in the body which extend l the ring grooves and to provide a clearance between said body and sleeve; said clearance extending from the upper edge of the sleeve portion downwardly to a point intermediate its upper and lower edges, the main body portion being provided with openings to permit circumferential expansion of said body without causing radia'l distention of the sleeve portion, and 2t portion integral with said sleeve extending diametric llythrough the body portion by means of szid openings therein.

Signed at New York city, in the county of New York and State of New York, this- 20th day of March, A. D. 1925.

\WALTER o. BAUER. 

